EN 60112:2003

Method for the determination of the proof and the comparative tracking indices of solid insulating materials

Describes a method of test intended to indicate the relative resistance of solid electrical insulating materials to tracking for voltages up to 600 V when exposed under electric stress to water with the addition of contaminants on the surface. Has the status of a basic safety publication in accordance with IEC Guide 104.

Verfahren zur Bestimmung der Prüfzahl und der Vergleichszahl der Kriechwegbildung von festen, isolierenden Werkstoffen

Méthode de détermination des indices de résistance et de tenue au cheminement des matériaux isolants solides

Donne une indication de la résistance relative au cheminement des isolants électriques solides aux tensions inférieures ou égales à 600 V lorsque leur surface est exposée, sous contrainte électrique, à l'action d'eau contenant des impuretés ioniques. A le statut d'une publication fondamentale de sécurité conformément au Guide 104

Metoda za ugotavljanje preskusnih in primerjalnih indeksov ustvarjanja prevodnih poti trdnih izolacijskih materialov (IEC 60112:2003)

Standard določa preskusno metodo z izmeničnimi napetostmi za ugotavljanje preskusnih in primerjalnih indeksov ustvarjanja prevodnih poti trdnih izolacijskih materialov na kosih, vzetih iz delov opreme, in na ploščah materiala. Standard po potrebi zagotavlja ugotavljanje erozije. Rezultatov preskusa ni mogoče uporabiti neposredno za vrednotenje varnih plazilnih razdalj pri projektiranju električnih naprav. Ima status osnovne varnostne publikacije v skladu z IEC Vodilom 104. Večje spremembe od prejšnje izdaje so naslednje: Izbor materiala za določeno uporabo pogosto vključuje kompromise glede ravni posameznih lastnosti in preskusnih meril. V prejšnji izdaji IEC 60112 so preskusna merila zahtevala, da se »vzorec ne sežiga«, vendar je to izpostavilo dve vprašanji:
– težave pri prepoznavanju gorenja, ki vključuje vse vrste zgorevanja, npr. plamtenje in tlenje, v primeru, da je prišlo do iskrenja, kar je pogosto povzročilo nastanek ogljika na površini vzorca, in
– nekateri odbori za proizvode so v nekaterih primerih ugotovili, da je treba odpraviti merilo »brez sežiganja« pri preskusih ustvarjanja prevodnih poti, in so ga nadomestili s preskusom z gorenjem končnega proizvoda, s čimer sta nastali dve vrsti CTI/PTI z različnimi merili.

General Information

• Status: Published
• Publication Date: 31-May-2003
• Withdrawal Date: 28-Feb-2006
• ICS: 19.080 - Electrical and electronic testing
• ICS: 29.035.01 - Insulating materials in general
• Technical Committee: CLC/SR 112 - Evaluation and qualification of electrical insulating materials and systems (to be defined)
• Drafting Committee: IEC/TC 112 - IEC_TC_112
• Parallel Committee: IEC/SC 15E - IEC_SC_15E
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 12-Mar-2003
• Completion Date: 12-Mar-2003
• Ref Project: SIST EN 60112:2004 - Method for the determination of the proof and the comparative tracking indices of solid insulating materials

Relations

• Replaces: HD 214 S2:1980 - Method for determining the comparative and the proof tracking indices of solid insulating materials under moist conditions
• Effective Date: 29-Jan-2023
• Replaced By: EN IEC 60112:2020 - Method for the determination of the proof and the comparative tracking indices of solid insulating materials
• Effective Date: 14-Jun-2016
• Amended By: EN 60112:2003/A1:2009 - Method for the determination of the proof and the comparative tracking indices of solid insulating materials
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 60112:2004
01-april-2004
1DGRPHãþD
SIST HD 214 S2:1998

Metoda za ugotavljanje preskusnih in primerjalnih indeksov ustvarjanja prevodnih

poti trdnih izolacijskih materialov (IEC 60112:2003)

Method for the determination of the proof and the comparative tracking indices of solid

insulating materials

Verfahren zur Bestimmung der Prüfzahl und der Vergleichszahl der Kriechwegbildung

von festen, isolierenden Werkstoffen

Méthode de détermination des indices de résistance et de tenue au cheminement des

matériaux isolants solides
Ta slovenski standard je istoveten z: EN 60112:2003
ICS:
29.035.01 Izolacijski materiali na Insulating materials in
splošno general
SIST EN 60112:2004 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60112:2004
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SIST EN 60112:2004
EUROPEAN STANDARD EN 60112
NORME EUROPÉENNE
EUROPÄISCHE NORM March 2003
ICS 19.080; 29.035.01 Supersedes HD 214 S2:1980
English version
Method for the determination of the proof
and the comparative tracking indices
of solid insulating materials
(IEC 60112:2003)
Méthode de détermination des indices Verfahren zur Bestimmung der Prüfzahl
de résistance et de tenue und der Vergleichszahl
au cheminement des matériaux isolants der Kriechwegbildung von festen,
solides isolierenden Werkstoffen
(CEI 60112:2003) (IEC 60112:2003)

This European Standard was approved by CENELEC on 2003-03-01. CENELEC members are bound to

comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on

application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CENELEC member into its own language and

notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,

Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,

Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60112:2003 E
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SIST EN 60112:2004
EN 60112:2003 - 2 -
Foreword

The text of document 15E/209/FDIS, future edition 4 of IEC 60112, prepared by SC 15E, Methods of

test, of IEC TC 15, Insulating materials, was submitted to the IEC-CENELEC parallel vote and was

approved by CENELEC as EN 60112 on 2003-03-01.
This European Standard supersedes HD 214 S2:1980.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-12-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2006-03-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annex ZA is normative and annexes A and B are informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice

The text of the International Standard IEC 60112:2003 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following note has to be added for the standard indicated:

IEC 60587 NOTE Harmonized as HD 380 S2:1987 (not modified).
__________
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SIST EN 60112:2004
- 3 - EN 60112:2003
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

This European Standard incorporates by dated or undated reference, provisions from other

publications. These normative references are cited at the appropriate places in the text and the

publications are listed hereafter. For dated references, subsequent amendments to or revisions of any

of these publications apply to this European Standard only when incorporated in it by amendment or

revision. For undated references the latest edition of the publication referred to applies (including

amendments).

NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
Publication Year Title EN/HD Year
IEC 60589 1977 Methods of test for the determination of HD 381 S1 1979
ionic impurities in electrical insulating
materials by extraction with liquids
IEC Guide 104 1997 The preparation of safety publications - -
and the use of basic safety publications
and group safety publications
ISO 293 1986 Plastics - Compression moulding of test - -
specimens of thermoplastic materials
ISO 294-1 1996 Plastics - Injection moulding of test - -
specimens of thermoplastic materials
Part 1: General principles, and moulding
of multipurpose and bar test specimens
ISO 294-3 2002 Part 3: Small plates - -
ISO 295 1991 Plastics - Compression moulding of test - -
specimens of thermosetting materials
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SIST EN 60112:2004
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SIST EN 60112:2004
IEC 60112
Edition 4.0 2003-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Method for the determination of the proof and the comparative tracking indices
of solid insulating materials
Méthode de détermination des indices de résistance et de tenue au
cheminement des matériaux isolants solides
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX
ICS 19.080; 29.035.01 ISBN 2-8318-6804-1
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SIST EN 60112:2004
60112 © IEC:2003 – 3 –
CONTENTS

FOREWORD........................................................................................................................5

1 Scope........................................................................................................................... 9

2 Normative references....................................................................................................9

3 Terms and definitions.................................................................................................... 11

4 Principle....................................................................................................................... 13

5 Test specimen..............................................................................................................13

6 Test specimen conditioning........................................................................................... 15

6.1 Environmental conditioning...................................................................................15

6.2 Test specimen surface state................................................................................. 15

7 Test apparatus..............................................................................................................15

7.1 Electrodes............................................................................................................15

7.2 Test circuit...........................................................................................................17

7.3 Test solutions.......................................................................................................17

7.4 Dropping device...................................................................................................19

7.5 Test specimen support platform............................................................................ 19

7.6 Electrode assembly installation............................................................................19

8 Basic test procedure.....................................................................................................21

8.1 General................................................................................................................21

8.2 Preparation .......................................................................................................... 21

8.3 Test procedure.....................................................................................................23

9 Determination of erosion...............................................................................................23

10 Determination of proof tracking index (PTI) ................................................................... 23

10.1 Procedure............................................................................................................23

10.2 Report..................................................................................................................25

11 Determination of comparative tracking index (CTI) ........................................................ 25

11.1 General................................................................................................................25

11.2 Determination of the 100 drop point...................................................................... 25

11.3 Determination of the maximum 50 drop withstand voltage .................................... 27

11.4 Report..................................................................................................................29

Annex A (informative) List of factors that should be considered by product committees ...... 37

Annex B (informative) Electrode material selection ............................................................. 39

Bibliography......................................................................................................................... 41

Figure 1 – Electrode ............................................................................................................ 33

Figure 2 – Electrode / specimen arrangement ...................................................................... 33

Figure 3 – Example of typical electrode mounting and specimen support ............................. 35

Figure 4 – Example of test circuit......................................................................................... 35

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SIST EN 60112:2004
60112 © IEC:2003 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
METHOD FOR THE DETERMINATION OF THE PROOF
AND THE COMPARATIVE TRACKING INDICES
OF SOLID INSULATING MATERIALS
FOREWORD

1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, the IEC publishes International Standards. Their preparation is

entrusted to technical committees; any IEC National Committee interested in the subject dealt with may

participate in this preparatory work. International, governmental and non-governmental organizations liaising

with the IEC also participate in this preparation. The IEC collaborates closely with the International

Organization for Standardization (ISO) in accordance with conditions determined by agreement between the

two organizations.

2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an

international consensus of opinion on the relevant subjects since each technical committee has representation

from all interested National Committees.

3) The documents produced have the form of recommendations for international use and are published in the form

of standards, technical specifications, technical reports or guides and they are accepted by the National

Committees in that sense.

4) In order to promote international unification, IEC National Committees undertake to apply IEC International

Standards transparently to the maximum extent possible in their national and regional standards. Any

divergence between the IEC Standard and the corresponding national or regional standard shall be clearly

indicated in the latter.

5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with one of its standards.

6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject

of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60112 has been prepared by subcommittee 15E: Methods of test,

of IEC technical committee 15: Insulating materials.

This fourth edition cancels and replaces the third edition, published in 1979, of which it

constitutes a technical revision.
Major changes since the previous edition are the following:

The selection of a material for a specific application frequently involves compromises in the

levels of the individual properties and test criteria. In the previous edition of IEC 60112 the

test criteria required "no burning of the specimen", but this gave rise to two issues:

– difficulties in the identification of burning which includes all types of combustion, e.g.

flaming, and smouldering in the situation where scintillations had occurred giving rise in

many cases to carbon on the surface of the specimen, and

– a situation in which some product committees had found it necessary to dispense with the

"no burning" criterion in the tracking tests which they replaced by flame tests on the final

product, thereby giving rise to two types of CTI/PTI with different criteria.
This standard attempts to regularize this situation.

It has the status of a basic safety publication in accordance with IEC Guide 104.

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SIST EN 60112:2004
60112 © IEC:2003 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
15E/209/FDIS 15E/213/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this publication will remain unchanged

until 2015. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

The contents of the corrigenda of June 2003 and October 2003 have been included in this

copy.
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SIST EN 60112:2004
60112 © IEC:2003 – 9 –
METHOD FOR THE DETERMINATION OF THE PROOF
AND THE COMPARATIVE TRACKING INDICES
OF SOLID INSULATING MATERIALS
1 Scope

This International standard specifies the method of test for the determination of the proof and

comparative tracking indices of solid insulating materials on pieces taken from parts of

equipment and on plaques of material using alternating voltages.
The standard provides for the determination of erosion when required.

NOTE 1 The proof tracking index is used as an acceptance criterion as well as a means for the quality control of

materials and fabricated parts. The comparative tracking index is mainly used for the basic characterization and

comparison of the properties of materials.

Test results cannot be used directly for the evaluation of safe creepage distances when

designing electrical apparatus.

NOTE 2 This test discriminates between materials with relatively poor resistance to tracking, and those with

moderate or good resistance, for use in equipment which can be used under moist conditions. More severe tests,

of longer duration are required for the assessment of performance of materials for outdoor use, utilizing higher

voltages and larger test specimens (see the inclined plane test of IEC 60587). Other test methods such as the

inclined method may rank materials in a different order from the drop test given in this standard.

2 Normative references

The following referenced documents are indispensable for the application of this document.

For dated references, only the edition cited applies. For undated references, the latest edition

of the referenced document (including any amendments) applies.

IEC 60589:1977, Methods of test for the determination of ionic impurities in electrical

insulating materials by extraction with liquids

IEC Guide 104:1997, The preparation of safety publications and the use of basic safety

publications and group safety publications

ISO 293:1986, Plastics – Compression moulding test specimens of thermoplastic materials

ISO 294-1:1996, Plastics – Injection moulding of test specimens of thermoplastic materials –

Part 1: General principles, and moulding of multi-purpose and bar test specimens

ISO 294-3:2002, Plastics – Injection moulding of test specimens of thermoplastic materials –

Part 3: Small plates

ISO 295:1991, Plastics – Compression moulding of test specimens of thermosetting materials

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SIST EN 60112:2004
60112 © IEC:2003 – 11 –
3 Terms and definitions

For the purposes of this International Standard, the following definitions apply:

3.1
tracking

progressive formation of conducting paths, which are produced on the surface and/or within

a solid insulating material, due to the combined effects of electric stress and electrolytic

contamination
3.2
tracking failure
failure of insulation due to tracking between conducting parts

NOTE In the present test, tracking is indicated by operation of an over-current device due to the passage of

a current of at least 0,5 A for at least 2 s across the test surface and/or within the specimen.

3.3
electrical erosion
wearing away of insulating material by the action of electrical discharges
3.4
air arc
arc between the electrodes above the surface of the specimen
3.5
comparative tracking index
CTI

numerical value of the maximum voltage at which five test specimens withstand the test

period for 50 drops without tracking failure and without a persistent flame occurring and

including also a statement relating to the behaviour of the material when tested using

100 drops (see 11.4)

NOTE 1 The criteria for CTI may also require a statement concerning the degree of erosion.

NOTE 2 Although a non-persistent flame is allowed in the test without constituting failure, materials which

generate no flame at all are preferred unless other factors are considered to be more important. See also Annex A.

3.6
persistent flame
in case of dispute – one which burns for more than 2 s
3.7
proof tracking index
PTI

numerical value of the proof voltage in volts at which five test specimens withstand the test

period for 50 drops without tracking failure and without a persistent flame occurring

NOTE Although a non-persistent flame is allowed in the test without constituting failure, materials which generate

no flame at all are preferred unless other factors are considered to be more important. See also Annex A.

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SIST EN 60112:2004
60112 © IEC:2003 – 13 –
4 Principle

The upper surface of the test specimen is supported in an approximately horizontal plane and

subjected to an electrical stress via two electrodes. The surface between the electrodes is

subjected to a succession of drops of electrolyte either until the over-current device operates,

or until a persistent flame occurs, or until the test period has elapsed.

The individual tests are of short duration (less than 1 h) with up to 50 or 100 drops of about

20 mg of electrolyte falling at 30 s intervals between platinum electrodes, 4 mm apart on the

test specimen surface.

An a.c. voltage between 100 V and 600 V is applied to the electrodes during the test.

During the test, specimens may also erode or soften, thereby allowing the electrodes to

penetrate them. The formation of a hole through the test specimen during a test is to be

reported together with the hole depth (test specimen thickness). Retests may be made using

thicker test specimens, up to a maximum of 10 mm.

NOTE The number of drops needed to cause failure by tracking usually increases with decreasing applied voltage

and, below a critical value, tracking ceases to occur.
5 Test specimen

Any approximately flat surface may be used, provided that the area is sufficient to ensure that

during the test no liquid flows over the edges of the test specimen.

NOTE 1 Flat surfaces of not less than 20 mm × 20 mm are recommended to reduce the probability of electrolyte

loss over the specimen edge although smaller sizes may be used, subject to no electrolyte loss, e.g. ISO 3167,

15 mm × 15 mm multi-purpose test specimens.

NOTE 2 It is preferable to use separate test specimens for each test. If several tests are to be made on the same

test piece, care should be taken to ensure that the testing points are sufficiently far from each other so that

splashes or fumes from the testing point will not contaminate the other areas to be tested.

The thickness of the test specimen shall be 3 mm or more. Individual pieces of material may

be stacked to obtain the required thickness of at least 3 mm.

NOTE 3 The values of the CTI obtained on specimens with a thickness below 3 mm may not be comparable with

those obtained on thicker specimens because of greater heat transmission to the glass support through thinner test

specimens. For this reason, stacked specimens are allowed.

Test specimens shall have nominally smooth and untextured surfaces which are free from

surface imperfections such as scratches, blemishes, impurities, etc, unless otherwise stated

in the product standard. If this is impossible, the results shall be reported together with a

statement describing the surface of the specimen because certain characteristics on the

surface of the specimen could add to the dispersion of the results.
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SIST EN 60112:2004
60112 © IEC:2003 – 15 –

For tests on parts of products, where it is impossible to cut a suitable test specimen from a

part of a product, specimens cut from moulded plaques of the same insulating material may

be used. In these cases care should be taken to ensure that both the part and the plaque are

produced by the same fabrication process wherever possible. Where the details of the final

fabrication process are unknown, methods given in ISO 293, ISO 294-1 and ISO 294-3 and

ISO 295 may be appropriate.

NOTE 4 The use of different fabrication conditions/processes may lead to different levels of performance in

the PTI and CTI test.

NOTE 5 Parts moulded using different flow directions may also exhibit different levels of performance in the PTI

and CTI test.
In special cases, the test specimen may be ground to obtain a flat surface.

Where the direction of the electrodes relative to any feature of the material is significant,

measurements shall be made in the direction of the feature and orthogonal to it. The direction

giving the lower CTI shall be reported, unless otherwise specified.
6 Test specimen conditioning
6.1 Environmental conditioning

Unless otherwise specified, the test specimens shall be conditioned for a minimum of 24 h at

23 °C ± 5 K, with (50 ± 10) % RH.
6.2 Test specimen surface state
Unless otherwise specified,
a) tests shall be made on clean surfaces;

b) any cleaning procedure used shall be reported. Wherever possible, the details shall be

agreed between supplier and customer.

NOTE Dust, dirt, fingerprints, grease, oil, mould release or other contaminants may influence the results. Care

should be taken when cleaning the test specimen to avoid swelling, softening, abrasion or other damage to the

material.
7 Test apparatus
7.1 Electrodes

Two electrodes of platinum with a minimum purity of 99 % shall be used (see Annex B). The

two electrodes shall have a rectangular cross-section of (5 ± 0,1) mm × (2 ± 0,1) mm, with

one end chisel-edged with an angle of 30° ± 2° (see Figure 1). The sharp edge shall be

removed to produce an approximately flat surface, 0,01 mm to 0,1 mm wide.

NOTE 1 A microscope with a calibrated eyepiece has been found suitable for checking the size of the end

surface.

NOTE 2 It is recommended that mechanical means are used to re-furbish the electrode shape after a test to

ensure that the electrodes maintain the required tolerances, especially with respect to the edges and corners.

At the start of the test, the electrodes shall be symmetrically arranged in a vertical plane, the

total angle between them being 60° ± 5° and with opposing electrode faces approximately

vertical on a flat horizontal surface of the test specimen (see Figure 2 ). Their separation

along the surface of the test specimen at the start of the test shall be 4,0 mm ± 0,1 mm.

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SIST EN 60112:2004
60112 © IEC:2003 – 17 –

A thin metal rectangular slip gauge shall be used to check the electrode separation. The

electrodes shall move freely and the force exerted by each electrode on the surface of the

test specimen at the start of the test shall be 1,00 N ± 0,05 N. The design shall be such that

the force can be expected to remain at the initial level during the test.

One typical type of arrangement for applying the electrodes to the test specimen is shown in

Figure 3. The force shall be verified at appropriate intervals.

Where tests are made solely on those materials where the degree of electrode penetration is

small, the electrode force may be generated by the use of springs. However, gravity should be

used to generate the force on general purpose equipment (see Figure 3).

NOTE 3 With most, but not all designs of apparatus, if the electrodes move during a test due to softening or

erosion of the specimen, their tips will prescribe an arc and the electrode gap will change. The magnitude and

direction of the gap change will depend on the relative positions of the electrode pivots and the electrode/specimen

contact points. The significance of these changes will probably be material dependent and has not been

determined. Differences in design could give rise to differences in inter-apparatus results.

7.2 Test circuit

The electrodes shall be supplied with a substantially sinusoidal voltage, variable between

100 V and 600 V at a frequency of 48 Hz to 62 Hz. The voltage measuring device shall

indicate a true r.m.s. value and shall have a maximum error of 1,5 %. The power of the source

shall be not less than 0,6 kVA. An example of a suitable test circuit is shown in Figure 4.

A variable resistor shall be capable of adjusting the current between the short-circuited

electrodes to (1,0 ± 0,1) A and the voltage indicated by the voltmeter shall not decrease by

more than 10 % when this current flows (see Figure 4). The instrument used to measure the

value of the short-circuit current shall have a maximum error of ±3 %.
The input supply voltage to the apparatus shall be adequately stable.

The over-current device shall operate when a current with an r.m.s. value of 0,50 A with

a relative tolerance of ±10 %, has persisted for 2,00 s with a relative tolerance of ±10 %.

7.3 Test solutions
Solution A:

Dissolve approximately 0,1 % by mass of analytical reagent grade anhydrous ammonium

chloride (NH Cl), of a purity of not less than 99,8 %, in de-ionized water, having a conductivity

of not greater than 1 mS/m to give a resistivity of (3,95 ± 0,05) Ωm at (23 ± 1) °C.

NOTE 1 Select the quantity of ammonium chloride to give a solution in the required range of resistivity.

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SIST EN 60112:2004
60112 © IEC:2003 – 19 –
Solution B:

Dissolve approximately 0,1 % by mass of analytical reagent grade anhydrous ammonium

chloride, of a purity of not less than 99,8 %, and 0,5 % ± 0,002 % by mass of sodium-di-butyl

naphthalene sulfonate in de-ionized water, having a conductivity of not greater than 1 mS/m,

to give a resistivity of (1,98 ± 0,05) Ωm at (23 ± 1) °C.

NOTE 2 Select the quantity of ammonium chloride to give a solution in the required range of resistivity.

Solution A is normally used, but where a more aggressive contaminant is required, Solution B

is recommended. To indicate that Solution B was used, the CTI or PTI value shall be followed

by the letter "M".

The conductivity of the solutions shall be measured with alternating voltage at a frequency in

the range 1 kHz to 2 kHz. The procedure is described in IEC 60589.
7.4 Dropping device

Drops of the test solution shall fall on to the specimen surface at intervals of 30 s ± 5 s. The

drops shall fall more or less centrally between the electrodes from a height of 35 mm ± 5 mm.

The time for 50 drops to fall on to the specimen shall be (24
...